Police confirmed that a residential address in the area had been evacuated and was being searched, but declined to say if the operation was linked to the suspect arrested. He has not been charged or identified.

It was the fifth terrorist attack in Britain this year, following a vehicular and knife attack near Parliament in March, a suicide bombing at a rock concert in Manchester in May, and a van and knife attack around London Bridge and a van attack outside a London mosque, both in June.

It is understood the device had a timer, but Frank Gardner, the BBC's security correspondent, said the bomb appeared not to have gone off properly.